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Load flow analyses of reactive power in distribution system
Krátký, Michal ; Kašpírek,, Martn (referee) ; Topolánek, David (advisor)
This thesis is focused on issues with transmission of reactive power though the distribution line of E.ON area. The goal is to find out where and in what rate are overflows of reactive power and to project the correctional steps to minimize this overflow. In this solution, there were used data of dispatcher measurement, which were processed by created source code in Matlab. The processing was analyzed for final conclusion. There were discovered shortages in overflow of reactive power in transfer between distribution and transmission line and in unsuitably regulated capacity power factor in Planá power plant and wrong automatic regulation of turns in 440/110kV substation Dasný. The action to minimize overflows of reactive power was projected by decompensation reactor placed in T101 and T102 transformers in substation Tábor.
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Reducing transformer inrush
Zoufalý, Marek ; Bušov, Bohuslav (referee) ; Dohnal, Petr (advisor)
In this thesis is described the function and design of the transformer designed on ferromagnetic core, composed of transformer sheets. It is explained a transient inrush current of the transformer. In this work is inserted voltage and current waveforms, designed printed circuit board, serving to reduce the inrush current.
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Unit for wireless transmission of electrical energy
Jelínek, Aleš ; Kopečný, Lukáš (referee) ; Žalud, Luděk (advisor)
The aim of this work is to prove the practical applicability of the concept of contactless energy transfer using induction coils. The first part deals with the mathematical model and theoretical proof of the concept being able to work in practice and describes the process of detecting resonance of receiver circuit on transmitter side. Next chapter describes hardware solution of the experimental prototype. The last part contains measurement results of a coupling coefficient of coils and discusses performance and notable features of the prototype.
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Lead Acid Battery Charger
Jeleček, Ondřej ; Tonar, Karel (referee) ; Tošer, Pavel (advisor)
This diploma thesis is focused on design of lead acid baterry charger. First chapters describes the charging and discharging principes. This paper also shows basics types of lead acid batteries, their distribution depends on maintenance and part connected to the processes connected to the charging and discharging of the acumulators. Following part is focused on theoretical design of the charger with set up of parameters. Diploma thesis also contains comparsion of requested and real parameters of the charger.
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Calculation of transformer cooling
Hetflajš, Martin ; Cipín, Radoslav (referee) ; Janda, Marcel (advisor)
This master´s thesis deals with influence of forced air flow from the ventilators on the power transformer cooling. For this analysis was used simulation software ANSYS CFX, that uses the finite volume method for calculations of dynamic properties of liquids. In the introduction of the thesis is presented the basic terminology of fluid flow, temperature fields and theory of transformers. The simulation is divided to the analysis of flow through the left and right radiator models.
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Design of 22 kV Cable Network in the Existing Complex of Faculty Hospital
Blažek, Tomáš ; Procházka, Aleš (referee) ; Orságová, Jaroslava (advisor)
This thesis describes the reconstruction network 10 kV HV networks in a teaching hospital in the transition to a new 22 kV voltage level according to valid regulations. The paper describes the current state of technological equipment and its gradual replacement with new technology at 22 kV voltage level in each power units so as not to limit the operation of the hospital. For this purpose, the new backup system for rotating spare resources. The thesis deals with new input distribution, which will serve as a transfer point between the customer and distributor of electricity as well as advance the existing technological equipment.
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Optimalization of Induction Furnace Operation in foundry Vsetín
Trachta, Jiří ; Nowak, Stanislav (referee) ; Lázničková, Ilona (advisor)
The aim of this work is optimalisation of induction furnace in foundry for company PROMET FOUNDRY a.s. The company has two induction furnances. There are installed as identical construction. They have 2 modes of operation. First mode is founding and second mode is mode, where is temperature in maintain mode. Only one induction furnance can work in the founding mode at a time though. Inducion furnances are in the single-phase connection and they cause unbalance in the distribution network. Near the foundry there is a small network area whitch it is operated by company Zásobování teplem Vsetín a.s. The consumption of electrical energy in foundry so big, that in the year 2009 was made elaborate for Zásobování teplem Vsetín a.s. It was write at Laboratoře diagnostiky výkonů (Laboratory of performance diagnostics), which is a part of Electrotechnic Department at Technical Univarsity of Ostrava. The ordered study was named “Verification of causes of increased reactive energy consumption during transition from electricity delivery to electricity consumption”. The conclusion of this assignment confirms that in distribution network in the Jiráskova area in Vsetín there is unbalance of electrical energy and there is high part of reactive power. The next conclusion is crucial to find the customer who made the unbalance and to set relevant remedy. The last step will be the identification whether such device can actually be effectively balanced. It was subsequently proved that the Promet Foundry was causing the unbalance and that balanced consumption would be reasonable. Promet Foundry thus addressed Autel a.s. company with an inquiry to make a study of removing the causes of the unbalance which is caused by current induction furnaces operation at a minimum possible cost, least possible influence on the performance and minimum construction changes concerning the building. In this thesis there will be some topics. The result of which will be introducing of used heating technology, introducing of company and of effective plant performance and subsequent suggestions of possible unbalance removal or reactive power decrease. Several ways which are being implemented in the industry in order to balance consumption will be described. A suitable balancing plant will be subsequently chosen and its parameters will be calculated.
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Conceptual design of the reconstruction of an E.ON 22 kV distribution network installed at a specic area
Vepřek, Tomáš ; Nepevná, Vlastimila (referee) ; Blažek, Vladimír (advisor)
The aim of this thesis is a modification of the distribution network (DS) of the city of Brno to ensure power supply in the required quantity and quality for end consumers. Calculation of steady - state operation of distribution network (DS) of Brno is performed in the programme PAS DAISY Off-Line v.4.00 Bison. On the basis of available data (dispatching scheme, load current of stem lines and reserved power of wholesale customers) we will analyze the steady-state of network. We will find out which of the 110/22 kV transformer stations, cable and overhead lines are overloaded and perform network adjustments to ensure safe and reliable operation by 2015. We will identify in which year we will need to build a new power node in the northern part of Brno. The conclusion is focused on technical and economic evaluation of proposed alternative network arrangements.
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Stabilized operation and short - circuit conditions within E.ON 110 kV power network supplied from Slavětice 110 kV switching station, during the period of 2011
Nábělek, Ondřej ; Rampl, Martin (referee) ; Blažek, Vladimír (advisor)
In the Master Thesis discusses the impact of the bridge connecting the transformer to power system connection to a separate transformers. They were first analyzed the method of calculating the steady operation of the network using the Newton iterative method and the method of calculating short-circuit ratios. It describes the area Slavětice 110kV substation, which is the subject of subsequent calculations. It is also elucidating the function of the bridge connection, advantages and disadvantages. The reason for implementing the bridge operation is to increase the reliability of electricity supply to customers but the major disadvantage is the greater technical and economic performance because increased short circuit current and the need for transmission transformer 400/110kV same type with the same parameters. Point is the practical part, which contains already concrete results taken with the dispatcher software Sinaut. There is a short-circuit resistance compared to short-circuit power substation, then the burden of the elements (transformers, lines) for two specified connection alternatives and four interruptions important elements. Finally, it stated that it can be done with the bridge connection which technical measures. It was discovered that in terms of short-circuit ratios in the present time it is not possible to operate the bridge connection transformers substation Slavětice 110kV and in terms of very different parameters of transformers 400/110kV the operation is not recommended.
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The inverter for arc-welding
Vaculík, Josef ; Klíma, Bohumil (referee) ; Červinka, Dalibor (advisor)
This diplom thesis theoretically deals about principle of pulse welding current source. Work explains operation principle of the single acting transmit converter used in realized construction and mention the others examples of converters types. Goal of the work is design individual parts of source : input filter, pulse transformer, output inductor and power semiconductors components. Thesis also contains description of the regulation circuitry of the converter, auxiliary power supply and pre-driver for power transistors. If everything will be all right prototype of the source will be assembled and measured. Results will be compared with theoretical assumptions.
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